<!DOCTYPE HTML>
<html>
    <head>
        <title>Example</title>
        <meta name="author" content="Adam Freeman"/>
        <meta name="description" content="A simple example"/>
        <link rel="shortcut icon" href="favicon.ico" type="image/x-icon" />
    </head>
    <body>

        <progress id="myprogress" value="10" max="100"></progress>
        <p>
            <button type="button" value="30">30%</button>
            <button type="button" value="60">60%</button>
            <button type="button" value="90">90%</button>
        </p>
        
        <script>
            var buttons = document.getElementsByTagName('BUTTON');
            var progress = document.getElementById('myprogress');
            for (var i = 0; i < buttons.length; i++) {
                buttons[i].onclick = function(e) {
                    progress.value = e.target.value;
                };
            }
        </script>
    </body>
</html>
